1. Field of the Invention
The present invention relates to a display apparatus and an information input apparatus. In particular, the present invention relates to a display apparatus and an information input apparatus in which a touch sensor switch is provided on a pair of substrates opposed to each other.
2. Description of the Related Art
A display apparatus such as a liquid crystal display apparatus and an organic EL display apparatus has advantages of being thin, lightweight, and small in power consumption. Therefore, a display apparatus is widely being used for a mobile electronic apparatus such as a cellular phone and a digital camera.
Among such display apparatuses, a liquid crystal display apparatus has, as a display panel, a liquid crystal panel in which a liquid crystal layer is sealed between a pair of substrates. The liquid crystal panel is a transmissive type, and modulates and transmits illumination light emitted from an illumination apparatus such as a backlight provided on a back surface of the liquid crystal panel. The illumination light modulated causes an image to be displayed on a front surface of the liquid crystal panel.
The liquid crystal panel is an active matrix type, and includes a TFT (thin film transistor) array substrate in which a plurality of TFTs that function as pixel switching elements are formed. Further, in the liquid crystal panel, an opposed substrate is disposed so as to be opposed to the TFT array substrate, and a liquid crystal layer is provided between the TFT array substrate and the opposed substrate. In the active-matrix liquid crystal panel, a pixel switching element inputs a potential in a pixel electrode, thereby applying a voltage to the liquid crystal layer. Then, light transmitted through the pixel is controlled, thereby displaying the image.
In the display apparatus as described above, a touch panel as an information input apparatus may be provided on a display panel in some cases in order to allow a user to input operation data by using images such as icons displayed on a screen of the display panel.
However, in a case where the touch panel is externally provided on the display panel, an entire thickness of the display panel is increased, which may impair the advantage of being thin. In addition, providing the touch panel may cause a case where light that passes through the display area may be reduced or a case where the light may be interfered, which may result in a reduction in quality of the display image. Further, a problem of a reduction in manufacturing efficiency, an increase in manufacturing cost, or the like may arise.
In view of this, a display apparatus in which a touch panel function is implemented in a display panel has been proposed.
For example, a liquid crystal display apparatus in which a resistive touch sensor is built in a liquid crystal panel has been proposed.
In this case, the touch sensor includes a touch sensor switch formed by providing touch electrodes on the pair of substrates that constitutes the liquid crystal panel. When the liquid crystal panel is pressed and deformed, the touch electrodes are electrically connected with each other. In the liquid crystal panel, the touch electrodes are provided on a convex portion that protrudes in a convex shape so that the touch electrodes formed on the substrates are electrically connected with each other with a small external pressure (see, for example, Japanese Patent Application Laid-open Nos. 2001-75074, 2007-52368, and 2007-95044).